Invasive species

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Link to find invasive species: https://www.invasivespeciesva.org/

EXAMPLE OF DISCUSSION

Scientific Name: Trapa bispinosa

Common Name: Two-horned trapa

Kingdom: Plantae

When and How it was Introduced: The two-horned trapa was first introduced in Pohick Bay, within

the Potomac River near Lorton, Virginia in 2014. At first, many believed that it was the first

colony Trapa natans. After a DNA analysis was done, it was found that this was a different species that

is native to China, Taiwan, Japan, and Korea: Trapa bispinosa var. inumaii. Unfortunately, it's not

known how the two-horned trapa was introduced to Virginia freshwaters. There's speculation that they

were intentionally introduced as an ornamental plant for horticultural use. It could have also been an

accidental introduction where it was stuck on wildlife like the Canada goose, machinery, clothing, or in

shipping crates.

Environmental Effect: The two-horned trapa is identifiable as it has deltoid leaves that are green on top

and red underneath. They produce a pink flower that then seeds until frost. The fruits produced are 2

inch nuts with two sharp spines. This plant prefers freshwater habitats like lakes, ponds, and slow-

moving streams. This poses a threat to Virginia's freshwater ecosystems. Dense maps are formed that

can entirely choke or cover the surface of these bodies of water. Their continuous growth creates

competition with native submerged aquatic vegetation (SAV) and other species of plants. In the winter

time, their roots and leaves decay which causes reduced dissolved oxygen that leads to a weakened

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ecosystem. Additionally, the waters that contain a large amount of two-horned trapa makes boating,

fishing, and other recreational activities difficult. The horned fruits are sharp, posing additional harmful

risks as they can easily pierce through clothing and skin. Private property owners may have to pay large

sums of money to manage this plant and decreased enjoyment of their property in general.

Combating Environmental Effects:

It's important to have early detection of these invasive species to have better chances for eradication or

suppression. State and federal agencies, non- profit organizations, informed individuals, and volunteer

groups are working together to eradicate this invasive species. As soon as the two-horned trapa is

detected and reported, removal or treatment will begin. The trapa plants can be removed by hand and

composted in a dry area. All the plants must be harvested before seed-set to stop fertile seeds from

sprouting the next year. Continuous research is being done into the effectiveness of aquatic herbicide

against the two-horned trapa. All these efforts must be continued in the following years to ensure

eradication. As more trapa plants are being removed, the cost, and volume of harvests will decrease each

year. In Virginia, the two-horned trapa is in the process of being listed and regulated as a Tier 2 Noxious

Weed.

Works Cited

Sweany, Ag. “Two-horned Trapa.” ArcGIS StoryMaps, 2 Apr. 2024,

storymaps.arcgis.com/stories/05396b12d9384eb1a92f2bd66a19da64.

Two-Horned Trapa (Trapa Bispinosa) (U.S. National Park Service). www.nps.gov/articles/000/two-

horned-trapa-trapa-

bispinosa.htm#:~:text=Two%2Dhorned%20trapa%20(Trapa%20bispinosa)%20is%20an%20annual,near

%20Lorton%2C%20VA%20in%202014%20(Chorak%20et.&text=As%20of%202024%2C%20there%2

0are%20130%20observations,which%20are%20in%20Maryland%20and%20Northern%20Virginia

Links to an external site..

Two-horned Trapa. www.invasivespeciesva.org/species/two-horned-trapa.